Check out some similar questions!

jeepey · Apr 26, 2007, 11:32 PM

I have the following part to a problem that I am struggling with. (see diagram attachment)

The water tank has a nozzle with an unknown diameter at a depth of 6.75m. The level of the tank will stay the same depth by being toped up.

What I am struggling with is calculating what diameter the nozzle needs to be to exert a force of 4291.8N on the plate? Anyone point me in the right direction? :confused: :confused:

Thanks

Capuchin · Apr 26, 2007, 11:46 PM

Well we can use a formula for hydrostatic pressure:

$P = \rho g h$

Then we can use The formula for pressure:

$P = \frac{F}{A}$

The area is circular so

$A = \pi r^2$

Putting these together:

$\frac{F}{\pi r^2}= \rho g h$

$r = \sqrt{\frac{F}{\pi \rho g h}}$

$d = 2 \sqrt{\frac{F}{\pi \rho g h}}$

Does this help?

Keep in mind that this formula is quite approximate, so it might not give you as accurate a force as you are desiring here.

jeepey · Apr 27, 2007, 12:08 AM

Thanks that makes sense,
I've been told that bernoulli's law can be used to solve the problem, do you think it would be any more accurate?

Capuchin · Apr 27, 2007, 12:12 AM

I think bernoulli's law would require you to know the other dimensions of the tank.